There are many well-known methods of converting an analog input signal to a series of digital output signals, and of reversing the process to convert a series of digital input signals (a binary word) to an analog output signal. All such methods can be improved upon by reducing the number of components required, by reducing the time needed to convert a sampled signal, or by changing the circuit components so as to reduce component losses and the resulting inaccuracies associated with signal transfer, or by a combination of these methods.
It is therefore one object of the present invention to provide an A/D converter that requires few components, and is simple and inexpensive to construct.
It is another object of the present invention to provide an A/D converter that is equally accurate for positive and negative analog input signals.
It is another object of the present invention to provide an A/D converter that processes signals rapidly.
It is another object of the present invention to provide an A/D converter that produces a digital representation of the input signal without any diode losses.
It is yet another object of the present invention to provide an A/D converter constructed from substantially similar stages of circuitry.
It is yet another object of the present invention to provide an A/D converter having stages of circuitry that experience no diode losses.
It is yet another object of the present invention to provide an A/D converter that processes an input signal without using a clock.
It is yet another object of the present invention to provide an A/D converter having N stages that is cascadable.
It is still another object of the present invention to provide an A/D converter wherein the number of required components increases proportionately, not exponentially, with the increase in bit resolution.
It is finally an object of the present invention to provide an A/D converter that can also be used as a digital-to-analog (D/A) converter having all of the advantages set forth above.